Promiscuity is Key to Honeybee Colony Survival: Queen Bee's Mates Reveal Genetic Diversity

A honeybee queen has the obligation to not only produce as many insects as possible, but also to have as many mates as possible. New research reveals that genetic diversity is key to colony survival, which means that the more mates, the better.

"We knew genetic diversity affected survival under controlled conditions, but wanted to see if it held true in the real world," said David Tarpy, associate professor of entomology at North Carolina State University, in a news release. "And if so, how much diversity is needed to significantly improve a colony's odds of surviving."

In order to answer these questions, Tarpy collected genetic samples from 80 commercial colonies of honeybees in the eastern United States. He then assessed each colony's genetic diversity in order to find out exactly how many males a colony's queen has mated with; the more genetic diversity there was, the more males the queen had. The scientists then tracked the health of the colonies on an almost monthly basis over the course of 10 months, the working season for commercial bee colonies.

It turns out that more genetic diversity is better. Colonies where the queen had mated with at least seven different males were 2.86 times more likely to survive the working season. In fact, 48 percent of colonies with queens who had mated seven times or more were still alive at the end of the season. That's a huge contrast to the mere 17 percent of colonies that had a queen that mated less than seven times.

"Forty-eight percent survival is still an alarmingly low survival rate, but it's far better than 17 percent," said Tarpy in a news release. "This study confirms that genetic diversity is enormously important in honeybee populations. And it also offers some guidance to beekeepers about breeding strategies that will help their colonies survive."

Beekeepers may need all the help they can get. Honeybees across the United States and the world are suffering from Colony Collapse Disorder (CCD), the phenomenon where entire colonies can die off. Parasites, monoculture, a changing climate and other factors are all leading toward a future where there may not be enough bees in order to pollinate all of our crops. Since bees pollinate everything from apples to cucumbers, this new study is crucial to showing what can be done in order to help stave off CCD and other colony diseases.

The findings are published in the journal Naturwissenschaften.